What command/tool do you use to get the feature table?
If you dealing with OTUs obtained by VSEARCH, you may be able to output the file listing in which OTU fell each sequences. So you can do a bit of scripting to merge all the info into a final table.
If you got ASVs, the things is a bit more complicate because I don’t think dada2 and deblur tracks the destiny of each sequences after the denoising, but just pull out the final count for each unique ASV obtained.
A potential way for you to do what you need is to align back all the sequences onto the sequence feature file (vsearch may do that for you), and from the output file figure out the best match for each sequence. Then, again, merge all the info with a bit of scripting.
(The other way I can see is to taxonomy classify all the sequences, but I assume it is not doable of course …)
I hope it make sense, and it is helpful